Pile cranberries into the bowl of a food processor and pulse until uniformly chopped, working in batches if needed. Transfer to a mixing bowl.
12 ounces fresh cranberries
Sprinkle 1/4 cup sugar over the cranberries and stir well. Set aside to macerate for 10 minutes, letting the cranberries absorb the sugar and draw out the juices.
1/4 to 1/3 cup granulated sugar
After the cranberries have rested, add the jalapeños, green onion, cilantro, red onion if using, and lime juice. Stir well until uniformly mixed, then stir in a pinch of salt.
2 jalapeños, 2 green onions, 1/4 cup chopped fresh cilantro, 1/4 cup diced red onion, 1 tablespoon lime juice, Pinch fine sea salt
Taste and adjust as needed, adding more sugar, jalapeño, or salt as needed.
Serve immediately, or cover and chill to let the flavors meld. Before serving, stir to reincorporate any settled juices.
Notes
Makes about 2.5 cups.
If your cranberries come in 10 ounce bags, that will work here, no substitutions needed.
Start with the lesser amount of sugar and add more as needed.
Store in an airtight container in the fridge for 3 days.